Biological Effects Of Gold Nanorods On Different Subtypes Of Breast Cancer Cells

The incidence rate of breast cancer is the highest in the incidence rate of malignant tumors worldwide.Traditional treatments and radiotherapy of breast cancer can not only kill cancer cells,but also damage normal cells and cause damage to the human.Therefore,it is particularly important to study new safe detection and treatment methods with little damage to the human body.In recent years,gold nanorods(GNRs)have been widely used in nanomedicine and biomedicine because of their excellent physical and chemical properties and high photothermal conversion efficiency.The mode of cell death induced by GNRs is a key problem in practical treatment.The biotoxicity of GNRs to cells is a complex process,including the cytotoxicity of GNRs,cell cycle and apoptosis,cell membrane integrity and a series of effects on cell mitochondria.In this experiment,the physical and chemical properties of different coated GNRs were synthesized and characterized.Secondly,we studied the interaction of different subtypes of breast cancer cell lines(MCF-7 and MDA-MB-231)with different encapsulated GNRs,including the cytotoxicity of different encapsulated GNRs at different concentrations on breast cancer cells and the effect on apoptosis of different subtypes of breast cancer cells.At the same time,flow cytometry was used to study the expression of oxidative stress in mitochondria of different coated GNRs in different breast cancer cells.Finally,the cell biological effect under photothermal therapy of GNRs was studied by laser scanning confocal microscope.Studies have shown that the biological effects of GNRs on different subtypes of breast cancer cells are concentration dependent.And the increase of the concentration of GNRs leads to the increase of cytotoxicity,apoptosis and reactive oxygen species.In the absence of light,the toxicity and apoptosis rate of GNRs on MDA-MB-231 cells were significantly higher than those of MCF-7 cells,which may be due to the higher production of reactive oxygen species in MDA-MB-231 cells.Mitochondria play an important role in cell apoptosis.The increase of LDH content with the increase of GNRs concentration indicates that GNRs can cause the rupture of breast cancer cell membrane,which is an important way of GNRs induced cell death.After illumination,GNRs have a significant effect on the activity of breast cancer cells,in which the photothermal treatment effect of MCF-7 cells is better than that of MDA-MB-231 cells,which is characterized by the increase of apoptosis rate and the production of reactive oxygen species.Photothermal therapy can kill cancer cells under the condition of low concentration of GNRs so as to achieve the purpose of treatment.This study provides evidence for the death mechanism of GNRs on different breast cancer cells and provides a research basis for the diagnosis and treatment of breast cancer in the future.